福州市性病门诊人群生殖道沙眼衣原体的分子流行病学研究

Molecular epidemiology of Chlamydia trachomatis in outpatients visiting STD clinics in Fuzhou,China

目的探讨福州市性病门诊人群泌尿生殖道沙眼衣原体的基因型分布状况。方法收集2013-2014年临床疑似生殖道沙眼衣原体感染者标本2 019份,用实时荧光定量PCR检测沙眼衣原体,阳性标本用套式PCR扩增Omp1区并进行测序分析。测序结果上传至BLAST网站查找序列的相似性、构建系统树确定基因型。结果检测沙眼衣原体阳性标本86份,成功分型的有83份,1株为混合感染。测得8个基因型,分别为:F型(36.59%)、E型(24.39%)、D型(12.20%)、G型(9.76%)、J型(9.76%)、H型(3.66%)、K型(2.44%)、B型(1.22%)。计算不同基因型间Omp1基因的核苷酸的同义突变率(dS)和非同义突变率(dN),发现仅G型的dN/dS值大于1,其他型均小于1。结论 F型和E型是福州市性病门诊人群泌尿生殖道沙眼衣原体的主要基因型。同义替代是Omp1基因在进化过程中的主要变异。

We investigated the distribution of Chlamydia trachomatis genotypes in the outpatients visiting STD clinics in Fuzhou City, China. Between 2013 and 2014, a total of 2 019 urethral or endocervicaI specimens from susceptible genital C. trachornatis infections were collected and detected by using real-time PCR assay kit. The C. trachornatis -positive specimens were subsequently amplified with nested PCR for Ompl region and analyzed by sequencing. Oenotyping was performed by BLAST similarity search and phylogenetic tree analysis. Eighty-three of the 86 C. trachornatis-positive specimens were suc- cessfully sequenced. Only one specimen was identified as multiple infection. Eight different genotypes were identified. The most prevalent was F （36. 59%）, followed by E （24. 39%）, D （12. 20%）, G （9. 76%）, J （9.76%）, H （3. 66%）, K （2.44%） and B （1.22% ）. Synonymous mutation rate and non-synonymous mutation rate among Ompl genes of different geno- types were calculated. All genotypes but O showed dN/dsvalues of〈l. Genotypes F and E were commonest. Synonymous sub- stitution was the major pattern of variation in the process of Ompl gene evolution.